The subject matter of the invention is compositions for the oxidative dyeing of hair based on 3,4- or 4,5-diaminopyrazol derivatives as developer substances and new 3,4- or 4,5-diaminopyrazol derivatives.
In the area of hair coloring, oxidation dyestuffs have achieved considerable importance. The coloring is brought about by means of the reaction of certain developer substances with certain coupler substances in the presence of a suitable oxidizing agent.
In particular, 2,5-diaminotoluene, 2,5-diaminophenylethyl alcohol, p-aminophenol and 1,4-diaminobenzene are used as developer substances. Resorcin, 4-chlororesorcin, 1-naphthol, 3-aminophenol, 5-amino-2-methylphenol and derivatives of m-phenylenediamine are among those coupler substances whose use is preferred.
Numerous special demands are placed on oxidation dyestuffs which are used for dyeing human hair. For example, they must be unobjectionable in toxicological and dermatological respects and must enable the desired intensity of coloring. In addition, a favorable fastness to light, permanent waving, acids and rubbing are required of the achieved hair dyes. But, in every instance, such hair dyes must remain stable over a period of at least 4 to 6 weeks without being influenced by light, rubbing or chemical agents. Moreover, it is necessary that a wide assortment of various color shades can be produced by means of combining suitable developer and coupler substances. In order to achieve natural and especially fashionable shades in the red area, 4-aminophenol is chiefly used, by itself or in a mixture with other developer substances, in combination with suitable coupler substances.
The developer 4-aminophenol, which was chiefly used previously for the red area of the color scale, has recently been criticized for not being physiologically tolerated, while developer substances such as pyrimidine derivatives, which have been recommended more recently, are not completely satisfactory with respect to coloring. The pyrazol derivatives described in DE-OS 2 I60 3I7 such as 3-amino-1-phenyl-2-pyrazolone-5 only dye hair to depths of color which are unusable in hair dyeing practice.